From mboxrd@z Thu Jan 1 00:00:00 1970 From: dave@horsfall.org (Dave Horsfall) Date: Sat, 13 May 2017 10:26:12 +1000 (EST) Subject: [TUHS] The evolution of Unix facilities and architecture In-Reply-To: <1494633169.1599957.975050752.2FB9B2DA@webmail.messagingengine.com> References: <20170512233012.7B9DB18C099@mercury.lcs.mit.edu> <1494633169.1599957.975050752.2FB9B2DA@webmail.messagingengine.com> Message-ID: On Fri, 12 May 2017, Random832 wrote: > > > if (xp->x_count!=1 || xp->x_iptr->i_mode&ISVTX) > > > goto error; > > > > Err, isn't that the sticky bit, not the setuid bit? > > The sticky bit makes it keep the image in memory when there are no > processes using it. I assume x_count is determining whether there are > processes using it. So, taken together, these checks are "is there or > might there be in the future a process, other than the one being > debugged, using this exact copy of the image rather than loading it from > the disk". I know that, but the discussion was about the SUID bit, and the ability to modify the in-core image of a set-uid program being run... -- Dave Horsfall DTM (VK2KFU) "Those who don't understand security will suffer."